Technical Field
The present invention relates to a coordinate detecting apparatus.
Description of the Related Art
In recent years, an electronic information board having a flat panel display, such as a liquid crystal display, equipped with a touch panel has been used in face-to-face or remote meetings, for example. Such an electronic information board detects the position of contact of an electronic pen or a finger of an operator, for example, on a display area of the display.
For example, to detect the contact of an object on the image display area, a plurality of light-receiving sensors (e.g., cameras) respectively including light-emitting members may be provided around the outer circumference of the image display area to detect light from the light-emitting members with the light-receiving sensors. In this case, if an object contacts the image display area, the light from the light-emitting members is intercepted at the point of contact, which is detected by triangulation based on the angle at which the light is intercepted.
Alternatively, a light-emitting pen including a light-emitting member may be used to detect light from the light-emitting member with a plurality of light-receiving sensors (e.g., cameras) disposed around the outer circumference of the image display area. In this case, if the light-emitting pen contacts the image display area, the light from the light-emitting member is incident on the light-receiving sensors, and the point of contact is detected by triangulation based on the angle of incidence of the light.